Reduce irregular spaces hints' noise and add command to replace them

[theletterf]

From @shainaraskas:

how much does this actually impact the output? it sneaks past our CI constantly and makes huge volumes of check annotations that I end up cleaning up by hand so my devs don't complain. wondering if it's actually introducing risk from your perspective. https://github.com/elastic/elasticsearch/pull/136829/files

My proposal:

• Create a command that fixes all irregular whitespaces (would this be the first docs-builder format use?)
• Emit a single hint pointing to the command.